Abstract

This study evaluated the health of the Chilean flounder Paralichthys adspersus inhabiting the marine coastal area influenced by the Itata River. Flounder were also sampled at two reference sites during the course of 1 year. The pathological examination was done following the ICES protocol: external and internal lesions, condition factor, hepatosomatic and spleen indexes, and number of erythrocytes, lymphocytes, and thrombocytes. The prevalence of fish with lesions differed significantly among sites. The flounder sampled in the Itata area were the most affected. The evaluation of the macroscopic lesions observed on the flounder caught in the Itata area revealed (1) seven different types of macroscopic lesions, (2) a high prevalence of epidermal irritation lesions, and (3) a normal K factor, hepatosomatic index, and blood cell count. Significant differences were found in epidermal irritation lesions between stages and sites and between sexes and sites. Juveniles and adults as well as males and females were affected. A seasonal analysis of the macroscopic lesions on the flounder caught in the Itata area showed significant differences for only the epidermal irritation lesions between the sampled seasons of the year; the flounder caught in winter 2006 had the highest prevalence (77%) of such lesions. These results are discussed in relation to the hydrographic conditions, the contents of inorganic, nutrient and other organic compounds in the water column, and the contents of organic compounds and metals in the sediments of the subtidal environment in the Itata area. © 2008 Springer Science+Business Media, LLC.